In general, wafer image processing involves an inspection system collecting an image of a wafer that has been fabricated from a particular design and processing the image for various purposes, such as to detect defects within the design and/or the wafer. However, this image processing typically requires a coordinate mapping between the wafer design and the wafer image. Just by way of example, with the dimensions of wafer features decreasing, defects likewise are becoming smaller. Within a wafer image these defects may be fuzzy due to their small size and therefore difficult to accurately pinpoint. Wafer to image mappings can allow for the above mentioned defects to be more accurately located within the design and/or image.
Unfortunately, current techniques for generating wafer design to image mappings are prone to error. In particular, these techniques rely on users manually making correlations between the design and image. Prior Art FIG. 1 illustrates a conventional method for a user to manually make the design/image correlations. As shown, a first screen 102 displays the design and a second screen 104 displays the wafer image. The user selects (e.g. by clicking) a location in displayed design and a location in the displayed wafer image, as illustrated by the “+” to make a correlation between the two locations.
As noted above, this manual-based wafer design to image mapping is generally prone to errors. Specifically, error may be introduced due to positioning inaccuracy of the stage of the inspection system on which the wafer is placed. As another example, error may be introduced due to the user making an inaccurate selection of a location on the design and/or image. As yet another example, as the user is clicking on a wireframe design and not on a rendered design image, the raw design does not match with the wafer image accurately unless the wireframe design is rendered accurately.
There is thus a need for addressing these and/or other issues associated with the prior art techniques used for generating wafer design to image mappings.